Sewage systems are set to be used to spot early signs of coronavirus as part of a new pilot project in the UK.
The Welsh Government has given almost £500,000 to a consortium led by Bangor University, working with Cardiff University, Public Health Wales and Dwr Cymru Welsh Water.
They are developing a monitoring programme that can measure the presence of Covid-19 in waste water.
Presence of the virus in human waste is common in almost all confirmed coronavirus cases.
The move comes after a waste water study in Italy showed that the coronavirus might have been present in the country as early as December.
Coronavirus has also been found in sewage in China.
Sampling will begin almost immediately in a small number of water treatment plants, rapidly expanding to up to 20 treatment plants that cover approximately 75% of the Welsh population, reports Wales Online.
At the same time as monitoring for coronavirus, the systems established will also be able to determine whether other types of respiratory viruses are also present which will aid public health monitoring.
Commenting on the pilot project, which will be funded for the next six months, Health Minister Vaughan Gething, said: "To halt the spread of the coronavirus we need to measure it within our communities and monitor changes.
"This pilot programme will allow us to develop an early warning system to provide signals on the levels of coronavirus infections in the community. This will complement our wider public health programmes, including testing.
"The funding provides the opportunity to build upon existing strengths and partnerships that we have in Wales in environmental sciences, disease surveillance and pathogen genomics. I’m pleased to be working with partners from across Wales."
The World Health Organisation (WHO) said there is currently no evidence that coronavirus has been transmitted via sewerage systems.
Professor Andrew Weightman, head of the Organisms and Environment Division at Cardiff University's School of Biosciences, said: "Knowledge of how this virus is spreading in the community is a vital part of preventing the spread, particularly as lockdown measures are eased.
"Waste water monitoring of Sars-CoV-2 provides an alternative approach. It's a simple way for us to determine the level of infection in a large community.
"Research suggests people start to shed the virus in faeces up to about two weeks before they get symptoms so this approach can also be used as an early warning system to indicate when levels of the virus are rising in the community.
"This will help us predict the potential re-emergence of Covid-19 outbreaks - and ultimately help us protect communities across Wales."
